Impaired Left Atrial Strain as an Early Marker of Cardiac Involvement in Type 2 Diabetes Mellitus: A Cross-Sectional Study.

Background: Diabetic cardiomyopathy is a major contributor to cardiovascular morbidity, often progressing silently before overt heart failure. Left atrial (LA) strain, assessed via speckle-tracking echocardiography, could serve as an early indicator of subclinical myocardial dysfunction in patients with type 2 diabetes mellitus (T2DM). Objectives: The objectives of this study were to evaluate LA strain parameters in patients with T2DM versus non-diabetic controls and investigate their association with glycemic control and diabetes duration. Methods: This cross-sectional study, designed according to STROBE reporting guidelines, included 47 participants (25 with T2DM and 22 controls) undergoing comprehensive echocardiographic and biochemical evaluation. LA reservoir (LASr), conduit (LAScd), and booster-pump (LASbp) strain values were measured. Associations with glycosylated hemoglobin (HbA1c) and diabetes duration were assessed via multivariate analysis. ROC curves were used to evaluate predictive performance. Results: Diabetic patients had significantly lower LASr (20.4 ± 7.25% vs. 26.7 ± 8.0%, p = 0.007), LAScd (-10.9 ± 5.4% vs. -15.6 ± 6.5%, p = 0.010), and LASbp (-9.9 ± 4.2% vs. -12.9 ± 5.0%, p = 0.034). LASr and LAScd remained independent predictors in multivariate models. ROC analysis showed good discrimination (AUC: LAScd = 0.78; LASr = 0.73). Conclusions: This study demonstrates that LASr and LAScd are independently associated with type 2 diabetes mellitus and can reliably identify subclinical atrial dysfunction before the onset of structural or symptomatic heart disease.